…for Sweden, it represents a serious breakdown in civil order. And something of a public-policy crisis. Sweden has a very welcoming immigration policy, and of course, an extremely generous welfare state. These things were supposed to protect Sweden from the class-and-ethnic conflict that has riven the United States, Britain, France. If those things don’t work–if you get riots anyway–then something in Swedish policy may need a rethink.

McArdle asks–but does not answer–the question, “Is immigration dangerous?” But that is likely the wrong question. The problem in Sweden–and they seem very aware of it–is immigration combined with a philosophy of multiculturalism that has promoted a separateness, bitterness, and resentment.

The rioters in Sweden were Muslim and certainly the ideology of Islam was part of the chaos, but Sweden’s multicultural policy choices literally added fuel to the fire–an open door policy that led to a fractionalized Muslim community that sees itself as separate from the nation in which they reside.

For years here in the United States, the forces of the institutional left have been pushing for not only immigration amnesty but also a radical anti-assimiliationist, multicultural agenda. These groups, including MALDEF and the National Council of La Raza, are the same ones that had major influence on the Gang of Eight legislation snaking its way through Congress right now.

The battle over comprehensive immigration reform is not actually about being pro- or anti-immigration. Despite the rhetoric, nobody is trying to stop all immigration. The real point of contention is about the path to citizenship plan, but the wider–and undiscussed–issue is about how we treat new immigrants and their relationship to the United States.

There are two paths for dealing with the immigration influx: the melting pot/assimilationist view or the multicultural/separatist view. Historically, the United States ideal was E Pluribus Unum: a nation made up of many different races and cultures, but the goal was to treat people first and foremost as individuals and then as Americans. As Woodrow Wilson said:

You cannot become thorough Americans if you think of yourself in groups. America does not consist of groups. A man who thinks of himself belonging to a particular national group in America has not yet beome an American.

That view of assimilation has vanished completely in modern America.

Things began to change in the 1960s as the left fragmented the country along ethnic identities. This became more and more entrenched as the left organized and developed a mainstream infrastructure. The Ford Foundation became a primary funding source for groups like MALDEF (The Mexican American Legal Defense and Education Fund) and the National Council of La Raza, who pushed for rights for illegal immigrants and drove an agenda that included teaching ethnic studies in public schools.

Here’s a brutally honest assessment of the problems caused by the multicultural agenda and the groups pushing it:.

The Afrocentric and bilingual curricula they would impose on the public schools are well-designed to exclude minority children from the American mainstream. They tell minority groups that the Western democratic tradition is not for them. They encourage minorities to see themselves as victims and live by alibis rather than to claim the opportunities opened for them by the potent combination of minority protest and white guilt. They fill the air with recrimination and rancor and have, remarkably, advanced the fragmentation of American life.

Study that paragraph well, because there are two remarkable things about it. First, it was written in 1992, about twenty years ago. Since then, multiculturalism has become the rule of the day and the consequences have been exactly as described. Second, it was written by a Democrat activist; Kennedy historian Arthur Schlesinger Jr. It’s from his book The Disuniting of America, a blistering, informed attack on multiculturalism that’s a must-read, if for no other reason than to see how far the liberal mainstream has gone hard left on multiculturalism in less than two decades. Comments like Schlesinger’s would be refreshing and rare from a Republican today and completely unheard of from a Democrat.

We didn’t abandon the melting pot as the result of a referendum or some national discussion. There are organized, well-funded forces on the institutional left who have been working for years on these issues, day in and day out. Despite that, events are unfolding that make seeing the real world consequences of multiculturalism impossible to ignore. The anti-Western views that are part of what keep the separatists separate have violent consequences, as we’ve seen recently in the suburbs of Sweden, the streets of London, and the finish line of the Boston Marathon.

Maybe it’s time we had that conservation about where we’re headed as a nation. Will America chose the melting pot or the powder keg?